linux/drivers/clocksource/timer-sp804.c
Daniel Lezcano 1727339590 clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE
The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the
clocksource at early stage. However, this macro is also used to initialize
the clockevent if any, or the clockevent only.

It was originally suggested to declare another macro to initialize a
clockevent, so in order to separate the two entities even they belong to the
same IP. This was not accepted because of the impact on the DT where splitting
a clocksource/clockevent definition does not make sense as it is a Linux
concept not a hardware description.

On the other side, the clocksource has not interrupt declared while the
clockevent has, so it is easy from the driver to know if the description is
for a clockevent or a clocksource, IOW it could be implemented at the driver
level.

So instead of dealing with a named clocksource macro, let's use a more generic
one: TIMER_OF_DECLARE.

The patch has not functional changes.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-14 11:58:45 +02:00

339 lines
7.5 KiB
C

/*
* linux/drivers/clocksource/timer-sp.c
*
* Copyright (C) 1999 - 2003 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/clk.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/sched_clock.h>
#include <clocksource/timer-sp804.h>
#include "timer-sp.h"
static long __init sp804_get_clock_rate(struct clk *clk)
{
long rate;
int err;
err = clk_prepare(clk);
if (err) {
pr_err("sp804: clock failed to prepare: %d\n", err);
clk_put(clk);
return err;
}
err = clk_enable(clk);
if (err) {
pr_err("sp804: clock failed to enable: %d\n", err);
clk_unprepare(clk);
clk_put(clk);
return err;
}
rate = clk_get_rate(clk);
if (rate < 0) {
pr_err("sp804: clock failed to get rate: %ld\n", rate);
clk_disable(clk);
clk_unprepare(clk);
clk_put(clk);
}
return rate;
}
static void __iomem *sched_clock_base;
static u64 notrace sp804_read(void)
{
return ~readl_relaxed(sched_clock_base + TIMER_VALUE);
}
void __init sp804_timer_disable(void __iomem *base)
{
writel(0, base + TIMER_CTRL);
}
int __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
const char *name,
struct clk *clk,
int use_sched_clock)
{
long rate;
if (!clk) {
clk = clk_get_sys("sp804", name);
if (IS_ERR(clk)) {
pr_err("sp804: clock not found: %d\n",
(int)PTR_ERR(clk));
return PTR_ERR(clk);
}
}
rate = sp804_get_clock_rate(clk);
if (rate < 0)
return -EINVAL;
/* setup timer 0 as free-running clocksource */
writel(0, base + TIMER_CTRL);
writel(0xffffffff, base + TIMER_LOAD);
writel(0xffffffff, base + TIMER_VALUE);
writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
base + TIMER_CTRL);
clocksource_mmio_init(base + TIMER_VALUE, name,
rate, 200, 32, clocksource_mmio_readl_down);
if (use_sched_clock) {
sched_clock_base = base;
sched_clock_register(sp804_read, 32, rate);
}
return 0;
}
static void __iomem *clkevt_base;
static unsigned long clkevt_reload;
/*
* IRQ handler for the timer
*/
static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
/* clear the interrupt */
writel(1, clkevt_base + TIMER_INTCLR);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static inline void timer_shutdown(struct clock_event_device *evt)
{
writel(0, clkevt_base + TIMER_CTRL);
}
static int sp804_shutdown(struct clock_event_device *evt)
{
timer_shutdown(evt);
return 0;
}
static int sp804_set_periodic(struct clock_event_device *evt)
{
unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE |
TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
timer_shutdown(evt);
writel(clkevt_reload, clkevt_base + TIMER_LOAD);
writel(ctrl, clkevt_base + TIMER_CTRL);
return 0;
}
static int sp804_set_next_event(unsigned long next,
struct clock_event_device *evt)
{
unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE |
TIMER_CTRL_ONESHOT | TIMER_CTRL_ENABLE;
writel(next, clkevt_base + TIMER_LOAD);
writel(ctrl, clkevt_base + TIMER_CTRL);
return 0;
}
static struct clock_event_device sp804_clockevent = {
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT |
CLOCK_EVT_FEAT_DYNIRQ,
.set_state_shutdown = sp804_shutdown,
.set_state_periodic = sp804_set_periodic,
.set_state_oneshot = sp804_shutdown,
.tick_resume = sp804_shutdown,
.set_next_event = sp804_set_next_event,
.rating = 300,
};
static struct irqaction sp804_timer_irq = {
.name = "timer",
.flags = IRQF_TIMER | IRQF_IRQPOLL,
.handler = sp804_timer_interrupt,
.dev_id = &sp804_clockevent,
};
int __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struct clk *clk, const char *name)
{
struct clock_event_device *evt = &sp804_clockevent;
long rate;
if (!clk)
clk = clk_get_sys("sp804", name);
if (IS_ERR(clk)) {
pr_err("sp804: %s clock not found: %d\n", name,
(int)PTR_ERR(clk));
return PTR_ERR(clk);
}
rate = sp804_get_clock_rate(clk);
if (rate < 0)
return -EINVAL;
clkevt_base = base;
clkevt_reload = DIV_ROUND_CLOSEST(rate, HZ);
evt->name = name;
evt->irq = irq;
evt->cpumask = cpu_possible_mask;
writel(0, base + TIMER_CTRL);
setup_irq(irq, &sp804_timer_irq);
clockevents_config_and_register(evt, rate, 0xf, 0xffffffff);
return 0;
}
static int __init sp804_of_init(struct device_node *np)
{
static bool initialized = false;
void __iomem *base;
int irq, ret = -EINVAL;
u32 irq_num = 0;
struct clk *clk1, *clk2;
const char *name = of_get_property(np, "compatible", NULL);
base = of_iomap(np, 0);
if (!base)
return -ENXIO;
/* Ensure timers are disabled */
writel(0, base + TIMER_CTRL);
writel(0, base + TIMER_2_BASE + TIMER_CTRL);
if (initialized || !of_device_is_available(np)) {
ret = -EINVAL;
goto err;
}
clk1 = of_clk_get(np, 0);
if (IS_ERR(clk1))
clk1 = NULL;
/* Get the 2nd clock if the timer has 3 timer clocks */
if (of_count_phandle_with_args(np, "clocks", "#clock-cells") == 3) {
clk2 = of_clk_get(np, 1);
if (IS_ERR(clk2)) {
pr_err("sp804: %s clock not found: %d\n", np->name,
(int)PTR_ERR(clk2));
clk2 = NULL;
}
} else
clk2 = clk1;
irq = irq_of_parse_and_map(np, 0);
if (irq <= 0)
goto err;
of_property_read_u32(np, "arm,sp804-has-irq", &irq_num);
if (irq_num == 2) {
ret = __sp804_clockevents_init(base + TIMER_2_BASE, irq, clk2, name);
if (ret)
goto err;
ret = __sp804_clocksource_and_sched_clock_init(base, name, clk1, 1);
if (ret)
goto err;
} else {
ret = __sp804_clockevents_init(base, irq, clk1 , name);
if (ret)
goto err;
ret =__sp804_clocksource_and_sched_clock_init(base + TIMER_2_BASE,
name, clk2, 1);
if (ret)
goto err;
}
initialized = true;
return 0;
err:
iounmap(base);
return ret;
}
TIMER_OF_DECLARE(sp804, "arm,sp804", sp804_of_init);
static int __init integrator_cp_of_init(struct device_node *np)
{
static int init_count = 0;
void __iomem *base;
int irq, ret = -EINVAL;
const char *name = of_get_property(np, "compatible", NULL);
struct clk *clk;
base = of_iomap(np, 0);
if (!base) {
pr_err("Failed to iomap\n");
return -ENXIO;
}
clk = of_clk_get(np, 0);
if (IS_ERR(clk)) {
pr_err("Failed to get clock\n");
return PTR_ERR(clk);
}
/* Ensure timer is disabled */
writel(0, base + TIMER_CTRL);
if (init_count == 2 || !of_device_is_available(np))
goto err;
if (!init_count) {
ret = __sp804_clocksource_and_sched_clock_init(base, name, clk, 0);
if (ret)
goto err;
} else {
irq = irq_of_parse_and_map(np, 0);
if (irq <= 0)
goto err;
ret = __sp804_clockevents_init(base, irq, clk, name);
if (ret)
goto err;
}
init_count++;
return 0;
err:
iounmap(base);
return ret;
}
TIMER_OF_DECLARE(intcp, "arm,integrator-cp-timer", integrator_cp_of_init);